Nut lock



y 1931. w. STEINHORST 1,816,551

NUT LOCK Filed Dec. 7. 1929 Patented July 28, 1931 WILHELM s'rnINHoRs'r,

NUT LOOK 1 Application filed December 7, 1929, Serial lTo.

My invention relates to locking devices for automatically locking nuts and like revolvable clamping elements in their tightened position, and more particularly to improvements in the design and manufacture of I Washers which are provided with teeth at their upper and lower face, biting into and thus mutually interlocking the nut and the respective substructure.

Amongst washers of this class a special type is known in the art, which are formed with a plurality of sector-shaped flaps, arranged closely side by side and which are helically bent so as to present teeth like projections at the upper and lower face of the washer.

The principal object of this invention is to provide improved washers of the type con-' cerned, which are safe against losing their locking power.

The invention further aims at providing improved tools of simple design which can be made at relatively low cost and will permit of producing the Washers concerned from 2.5 blanks in but two stamping operations. 7

Other objects of the invention will be apparent hereinafter.

. The nature and scope of the invention are briefly outlined in the appended claim and I will be more fully understood from the following specification takentogether with the accompanying drawings, in which Fig. 1 is a plan view of an improved washer, shown by way of an example,

Fig. 2 is a crosssection taken on line II in Fig. 1,

Figs. 3 and l diagrammatically show the shape, arrangement and cooperation of the cutting, bending and stretching elements of special dies as proposed for producing washers of the improved design in but two stamping operations.

In the blanks S from which washers of the improved desgn are to be made sector-shaped flaps Z, Z, Z are formed closely arranged side by side viz. in juxta-position to each other, by helically cutting into the blank; said flaps are then helically bentas seen in Fig. 2so as to present teeth-like projections at the upper and lower face of the washer, and are 412,557, and in German-y December, 8 1928.

against being permanently re-bent into their original flat position and incidentally losing their property as looking elements.

I am aware that attempts have been made by other inventors to accomplish the afore said stretching operation in a different manner viz. by forming the flat blank prior to cutting and bending the sector-shaped flaps with a conically upturned collar having a relatively longer edge than the respective origm inal edge;

However by cutting the said collar into sector-shaped flaps and re-bending the latter, in-' to a helically directed position in which the flaps partly overlap each other the material is subjected to undue stresses far beyondits elastic limit and is'liable to break. 7

The said drawbacks in the manufacture of Washers of the type concerned have been overcome by thedescribed improved tool by which the flaps are laterally stretched after having been out. 7

I propose to use a pair of stretching dies 0, u. The cutting and bending elements of the upper and lower die, diagrammatically shown in Figs. and 5 are of identical form viz. representing convex shaped projections 29,17, p, t, t, t", which are spaced from each other so as to permit of laterally stretching the flaps Z of the washer in a subsequent operation. s

For stretching the flaps one and the same set of dies 0, u may be used after the upper or lower die has been turned around its axis through an angle commensurate with the spaces between the cutting and bending elements of the dies as indicated in Fig. 4or another set of dies 0, 'u may be used of which the upper die and lower are permanently in the appropriate position for stretching the flaps Z of the washers in the manner and for the purpose described above.

Various modifications may be madein the design of tools used for the purpose concerned, without substantially deviating from the spirit and the leading ideas of my invention, e. g., instead of arranging the flaps atthe inner periphery of the Washer sectorshaped flaps may be similarly provided at the outer periphery or on both sides.

What I claim is I In a tool for producing .a nut lock Washer of the type set forth" including in combination a pair of crown shaped dies having Work- 9 ing faces of identical form and'being cooperatively associated in opposed position to-ea'ch other, so as to be capable of being axially movable relatively to each other and atth-e same time to be displaceable throughan vangle relatively to e'ach other, "the said Working faces having convex shaped lteeth which are spaced from "each other, their angula'rdisplacement being commensurate to -the spaces between the said-teeth. p

In testimony whereof 1 have signedmy name to this specification.

WILHELM STEINHORST. 

